Mr Mold said no final decisions had been taken but has now signed an executive order for the site which will cost £4.582m – making the total site cost £25.132m.

He says the police force simply could not function without the building in the long term when they move out of their Wootton hall HQ.

He said: “Over the past 30 years the police estate hasn’t been invested in.

“My predecessor sold Wootton Hall on the afternoon before I took office so that’s necessitated this to move quite quickly.

“What we want to make sure is that we deliver an estates strategy to make sure we have a place where people want to work and is efficient to work in.

“That to be frank is not going to be without cost.

“At the minute we are training the brightest and best to look after us in Northamptonshire in portable buildings at Wootton Hall.

“Doing that we’re not going to attract the people to protect us in the modern world.

“We couldn’t function without the new training centre because basically we wouldn’t meet our legal requirements for training and we wouldn’t be able to adapt to modern crime.”

The proposed two-storey, 1,588 sq m building will feature a staff training centre, office accommodation with flexible classrooms and meeting rooms, a sports hall to double up as lecture theatre with retractable seating for 80 people, a fitness suite and gym.

If the plans are approved by Kettering Council, work on the site could start by 2018.

The force is currently facing a £3.1m financial black hole – although £700,000 of this is described by the commissioner’s office as being ‘planned overspend’ – but Mr Mold has defended spending £4.5m more.

He said: “This is a facility that if approved we will be using for the next 30 years and it will take us that long to pay for it because we’ll finance it that way to make sure it doesn’t impact on policing.

“At the moment we don’t have classrooms and the capability to train our cyber cops.

“A modern training facility allows us to do that and by building on a major campus already means that running costs will be saved.

“My job is to make sure I give as much money as I can to the chief constable for him to deliver modern policing and to protect people from harm.

“This is great value for money and we have to make sure we look after people.

“Moving out of Wootton Hall and moving here will save us something in the region of £40m in running costs.

“This needs to be seen in the context of several programmes, one is technological evolution that going to enable us to put our cops back out there.

“Too many people say they don’t see the visibility and the reality is I’m not going to be able to magically change that but we can make sure that there are more hours spent on the street.”